The white labeling seems to be glued and dissolves with every key stroke more and more from. If you scratch just a little with your fingernail on the letter, dissolves all off ..... and while writing it naturally comes often times just short with his fingernails on the keyboard.
It will not be very long, then most letters and numbers are no longer legible.
Mess what Logitech sold there.
Alone for this reason, the keypad is absolutely useless, and can not be recommended.